I seem to remember that sex researchers have indicated that men and women get sexually aroused in different ways and at different rates. Men are aroused by visual stimuli -- and they get aroused quickly and easily. Women are more sensual/tactile/... something -- and it takes them longer.
Why?
Visualize the "doggie style" position for each gender. She's on all fours, facing away from the male. She probably has her knees apart. She may have her face on the ground. The male is directly behind the female. Let's say he's already on his knees.
What can he see of her? He can see her hips and her genitals (and, of course, legs, feet, etc), but virtually nothing of her upper body. She "presents" (that's the anthropological term) in this manner, he SEES her invitation, and he promptly gets aroused.
What can she see of him? Absolutely nothing. Nothing about her involvement in the sex act is visual. She only knows what he's doing when she feels him do it.
I submit that this explains the findings of the sex researchers (and if any of them came to the same conclusion, I don't know).
